WP3: Rail Passenger Transport - TOSCA Project

3.4 Incremental improvements and higher speed
General trends
Despite slightly higher average speeds and a modest priority for energy-saving measures in the
rail sector until recently, specific energy consumption has declined. For example, in the period
1990–2007 the Deutsche Bahn reduced its specific primary energy use by about 20 % in
passenger transport and about 35 % in freight (UIC, 2008), while Swedish railways reduced its
specific final electric and diesel energy use by about 11 % on average (SIKA, 2008). The
German case means an average saving of about 2 % per year, including efficiency improvements
both in electric power generation and in train efficiency, as well as higher load factors.
The Swedish case relates to train and feeding systems efficiency only and is about 0.7 % per
year. At least half of these improvements are estimated to be due to larger steps in new
passenger train technology, while the rest is due to continuous incremental improvements.
In the future increased attention is expected to be paid on energy and emission issues.
Therefore, the general historical trend of incremental improvement is supposed to continue at
least at the same rate as in the Swedish case, i.e. by about 0.3 % per year in relation to the total
rail energy consumption, excluding increased efficiency due to larger steps and improvements.
Incremental improvements – in particular reduced energy losses
Incremental improvements – besides the larger measures PA–PI in the railway system as
described above – are possible. Examples include: comfort energy reduction, traction and
auxiliary systems with reduced losses as well as reduced losses in the railway’s electric supply
systems. Until 2050 it is anticipated that a saving of 12 % will be reached compared with the
2009 reference, considered here as a single measure. This is equivalent to 30 % reduction of
the losses in electric rail operations, as losses, auxiliaries and comfort constitute about 40 % of
total energy consumption as an average. It is estimated that an energy saving of around 7 %
(out of 12) would be in reach for new trains until 2025 (UIC, 2010) (Railenergy, 2009), with
another 5 % assumed until 2050. Reduction in comfort energy can be facilitated by recovery of
heat, better controlled ventilation, heat pumps etc. Also losses in electric power equipment (on
trains and in supply systems) are assumed to be reduced, for example by introduction of
permanent magnet motors and more efficient converters. Similar improvements (totally 12 %
until 2050) are expected in diesel railway operations as well, due to improved efficiency in
diesel engines and in energy use for comfort and auxiliaries.
Rapid improvements are constrained by the long life of railway equipment (vehicles and fixed
installations). In the long term (say more than 15–20 years) the potential is higher if
progressive decisions are taken within the next 5–10 years. Many of these measures will be
motivated also for economic reasons.
Higher speed
There is a strong tendency to reduce travel time for several reasons, in particular increased
attractiveness against other modes but also improved productivity for trains and train crew.
These positive factors contribute to a modal shift to rail. In many cases (although not all)
reduced travel time will imply increased top speed, which, in turn, will imply increased energy
use with all other conditions equal. However, train technology is usually adapted to speed.
For the ‘Intercity or regional’ (electric) segment top speeds are estimated to increase (on
average) by 0.9 % per year, i.e. by 15 % until 2025 and by about 40-45 % until 2050. This
follows a general trend in top speeds for the last 150 years and there is no tendency or reason
that this continuing development should decline for the intercity or regional segment. This
segment is heterogeneous with top speed ranging from 100–120 km/h up to 220–240 km/h in
2009. The typical top speed is however quite low – about 160 km/h. For 2050 typical top
Deliverable D4 – WP3 passenger 12